1st Yardbird's pitchers are not Marshall pitchers They pick and chose parts of Marshall's mechanics that Yardbird calls tenets. That is not Marshall mechanics. Marshall does not condone Yardbird's Ala-Carte mechanics. My son has had hitting coaches including one that learned from Tony Gwynn and Ted Williams. My son's all star team had a BP that brought in a batting coach that was a recent high school graduate that was teaching hands to the ball. While my son was hitting the 18 year old instructor tried to provide input that my son ignored. When my son hit one out to right center, the coach proclaimed his success. My son rolled his eyes. The coach had nothing to do with it. Yardbird reminds me of that young high school graduate batting coach.
2nd ASMI, real doctors of medicine and bio-mechanics, have found Marshall's mechanics to be inefficient when compared to traditional mechanics. They threw with less velocity and accuracy while expending more energy and causing additional stresses to the shoulder.